Radiation detectors for detecting radiation using semiconductors are in practical use. It is necessary for related semiconductor radiation detectors to be of a thickness that is large enough to absorb radiation. Because of this, it is necessary to from p-n junctions using high-purity single-crystal semiconductors in order to provide depletion in this thick semiconductor to prevent generation of substantial leakage current.
For example, when the energy of detected radiation is 1 MeV or greater, a semiconductor of a thickness of 1 mm or more is necessary even when cadmium telluride having the largest absorption coefficient used in the semiconductors of the related art is adopted and complex pn junction structures for suppressing leakage current have to be adopted.
In addition, with radiation detectors adopting conventional silicon semiconductor or compound semiconductor such as gallium arsenide or cadmium telluride compound semiconductors etc., it is easy for the semiconductor element to become electrically damaged and deteriorate under a high-energy radiation environment of 1 kGy/h or greater such as for nuclear reactors, radioactive waste and its disposal facilities. It is therefore easy for operation to become unstable, for damage to be incurred during use over a short period of time, and for durability to be impaired. Further, with a radiation detector such as an iron dosimeter, the radiation dose cannot be measured at the location emitting the radiation, there is no immediacy, and usage limitations are therefore substantial.
An object of the present invention is therefore to provide a radiation detector, with a simple construction, capable of measuring radiation intensity in a stable manner across a broad range of radiation intensities including a high-intensity intensity range.